A whopping 3,000 families expecting to live in subsidized apartments this winter got an unpleasant holiday surprise: the rent vouchers they're holding are worthless.

The tenants were all living low-rent under a program that's beginning to expire - but had been promised they could still qualify for a federal Section 8 rent subsidy.

But this week, when many of them began to show up at New York City Housing Authority offices, which accepts the vouchers and administers the subsidy, they were told the program was kaput.

And they were out of luck.

"They said, 'There's no money,'" said garment worker Emil Yoanson, 55, who got the bad news when he showed up with a signed lease and a Section 8 voucher. "They wouldn't take the voucher."

His son, 5-year-old first-grader Christian, became upset when Yoanson tried to explain.

"He said, 'Daddy, what are we going to do? Are we going to have to go back to the shelter again?'" Yoanson said.

NYCHA Chairman John Rhea Thursday blamed the move - which could push thousands into the city's already crowded shelters - on Congress, a lower-than-usual attrition rate in the program and unprecedented demand.

"NYCHA has had to make the tough decision," Rhea said.

The decision will not affect families who already receive subsidies, but the agency will "not be issuing any new vouchers, period," he said.

More than half the vouchers - 1,833 - had been given to families and individuals who were once homeless.

Rhea, a former investment banker who took over the agency this year, said Congress didn't set aside enough money to run the program through the end of the year.

Congress took $58 million from the authority in May from funds that were earmarked for Section 8, Rhea said.

NYCHA and HUD have been locked in a long-running battle over how the city housing agency manages the money it receives from the federal government.